Component Operation & Testing - Heat Controller RG-51G Service Manual

RG-51G Service Manual
6. COMPONENT OPERATION & TESTING
WARNING:
DISCONNECT ThE POWER CORD FROM ThE POWER PLUG BEFORE SERVICING OR TESTING.
COMPRESSORS
Compressors are single phase, 115 volt, depending on the model unit. All compressor motors are permanent split
capacitor type using only a running capacitor across the start and run terminal.
All compressors are internally spring mounted and externally mounted
on rubber isolators.
COMPRESSOR WINDING TEST (See Figure 1)
Remove compressor terminal box cover and disconnect
wires from terminals. Using an ohmmeter, check
continuity across the following:
1. Terminal "C" and "S" - no continuity
- open winding - replace compressor.
2. Terminal "C" and "R" - no continuity
- open winding - replace compressor.
3. Terminal "R" and "S" - no continuity
- open winding - replace compressor.
GROUND TEST
Use an ohmmeter set on its highest scale. Touch
one lead to the compressor body (clean point of
contact as a good connection is a must) and the
other probe in turn to each compressor terminal
(see Figure 2.) If a reading is obtained, the
compressor is grounded and must be replaced.
ChECKING COMPRESSOR EFFICIENCY
The reason for compressor inefficiency is normally due to broken or
damaged suction and/or discharge valves, reducing the ability of the
compressor to pump refrigerant gas.
This condition can be checked as follows:
1. Install a piercing valve on the suction and discharge or liquid lines.
2. Attach gauges to the high and low sides of the system.
3. Start the system and run a "cooling performance test."
If test shows:
A. Below normal high side pressure.
B. Above normal low side pressure.
Room Air Conditioner with R-410A
7
Figure 1: Compressor winding test
Figure 2: Typical ground test
Heat Controller, Inc.